Rear seats in some vehicle are foldable towards the front to enlarge the storage space for users. However, when folding the rear seats, the seatbelts may interfere with the seat. Some technologies have been developed to solve the problem. For example, a fixing buckle is provided for the purpose of securing the seatbelt while it's not in use. Japanese Patent JP3745465B2 discloses a guiding structure for a seat belt. The vehicle seat is pivotable between a folded position and a use position while the guiding structure is also pivotable between two positions. When the seat is at the use position, the guiding structure guides the seat belt to a normal use position. During folding of the seat, the guiding structure pivots toward the vehicle side such that the seat belt moves to the vehicle side as well to avoid interference from the seat belt. The inventors have realized that, the guiding structure for the seat belt may increase cost as a separate part. Further, the guiding device is visible and thus affecting an appearance of the vehicle interior.